Asthma, the most common chronic condition of childhood, currently affects millions of adolescents. The rates, severity and adverse outcomes for those in poor minority populations are higher. One reason for this is the lack of adherence to medication among these adolescents. This team has developed a novel, developmentally appropriate, adolescent controlled, calendar-to-text messaging intervention suitable for use in primary care to improve adherence by promoting autonomy and control and prompting use of controller medications for these adolescents. We propose to conduct a pilot randomized controlled trial, in four Cincinnati Childrens based primary care clinics, of a texting interventio to increase adherence to preventive asthma medication among this poor minority population. We will achieve this objective though three specific aims: Aim 1: To determine the feasibility, acceptability, and use of a low intensity text messaging intervention to improve adherence to inhaled corticosteroid (ICS) therapy among high risk adolescents with persistent asthma recruited from 4 primary care practice sites. Aim 2: To determine effect sizes of the intervention to improve adherence (as measured by electronic monitoring and self report); clinical asthma control; and asthma related quality of life among adolescents with persistent asthma. Aim 3: To determine the temporal relationship between text message receipt and ICS canister actuation in order to understand mechanisms by which text messaging may increase ICS adherence. This research team is ideally suited to conduct this innovative trial. The senior investigators have worked together previously, including development of the preliminary data for this application. Our four primary care clinics also have an excellent track record of successful recruitment for clinical studies and a large number of adolescent patients with persistent asthma. Through this research, we will gather data on feasibility, usability and efficacy of the intervention that will ead to a future R01 application to examine the intervention's efficacy in a fully powered randomized trial.